Self-Consistent Calculations of Performance Parameters in Highly Doped Silicon-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistors

Abstract

The inversion-layer mobility, gate capacitance, transconductance and threshold voltage in highly doped silicon-on-insulator (SOI) n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) have been investigated for various SOI layer thicknesses (tSOI) using self-consistent calculations. It has been found for SOI MOSFETs with highly doped channels that, whenever tSOI (\\gtrsim2 nm) is reduced under the full-depletion condition, the current drive of SOI MOSFETs becomes higher than that of bulk MOSFETs because of the increase in the inversion-layer mobility. In such SOI MOSFETs, the total scattering rate of phonon and ionized impurity scatterings becomes lower with decreasing tSOI. These results are different from those of the previous work for SOI MOSFETs with low channel impurity concentration.